Power transmission



NQV. 21 1939. c, 2,180,817

POWER TRANSMISSION Filed Feb. 25, 1958 lee INVENTOR HUGH C. NYE.-

ATTORNEY FIG. 1

} Patented Nov. 21, 1939 UNITED STATES PATENT OFFICE"- POWER TRANSMISSION Hugh 0. Nye, Detroit, Mich, assignor to Vickers Incorporated, Detroit, Mich., a corporation of Michigan Application February 23, 1938, Serial No. 192,029

8 Claims. (01. 90-33) 5 This invention relates to power transmissions be withdrawn through a suction conduit I 2 by and more particularly to those of the fluid type a pump H. The pump I4 has a discharge con- Wherein a power transmitting fluid,.such as oil, duit IS in which thecustomary relief valve I8 is and hereinafter referred to as such, is utilized for inserted for directing oil to the tank through a the transmission of power between one or more by-pass conduit 20 whenever a predetermined 5 pumps and one or more fluid motors. pressure is exceeded in the conduit Hi. The con-- This invention is concerned with a power transduit l6 leads to the pressure port of a convenmission system particularly adapted for operating O a pr gc p n center -W Y V B a plurality of hydraulic motors in predetermined 22, which has its tank port connectedvto tank y sequence and may be used, for example, on a a'conduit 24. The cylinder ports of the valve 22 hydraulically operated broaching machine; Ma- Connect by Conduits and 28, With h rod and chines of this character are provided with a main he ds, r p vely, f a i ry y n er ram to which a pull broach may be detachably The latter h s reciprocably mounted therein secured after the'pilot end of the broach tool has a pi 3 e rod 31 of which is secured to it been inserted through a ho1e.in a work piece vertically movable main slide 30. The slide 30 The ram operates to pull the broach completely may be mounted in suitable ways in a broaching through the hole forming it to correct size and machine and d -P to carry a tool receiving shape as is well known in the art. It is customl h not shown for d hab y n a in h ary to, also provide means for handling the Pilot end o a br in 15001- broach tool while a finished work piece is removed A D p 33 has a Suction conduit 40 and a 1r0m the machine and a, "fresh ork piece i livery conduit 42 in which is inserted a relief inserted. Machines of this character have been 7 Valve 44 -P 011 to the tank ou providedheretofore with hydraulic t ol handling a conduit 45. The conduit 42 extends to the cylinders for this purpose. In certain classes of pressure port of a solenoid operated, closed work where large amounts of stock are to be 1561, y lv Which has its tank p removed in a single pass the broagh tool is very connected to tank by 9 conduit 48. The left hand long-and the free end thereof has a tendency to cylinder port of valve 46 connects by a conduit whip as it is pulled through the hole causin 50 which the'pressure port of asolenoid operated,

chattering'and inaccurate work. spring "centered, open center, four-way valve 52,

1 It is an object of the present invention to prohaving t tank Ports connected y a Conduit v54 vide a power transmission system suitable for W t t e k conduitla- The Cylinder Ports of operating a broaching machine and wherein the valve 52 are connected by conduits 56 and means are provided both for automatically 58 t the head and rod ends, respetively, of

handling the breaching-tool while it is discona pair of stationary cylinders 60,'which are connected from the main slide and also for positively nected in parallel; The cylinders 60 carry pisholding the free end of the tool against whip tons -62 reciprocably mounted therein. A con- .throughout a major portion of its working stroke, duit 64 branches on from the delivery conduit It is also an object of the present invention to l5 and 00111160175 t0 the right h cylinder P provide a power transmission system for operat- 0f Valve i i I ing a broaching machin of thi character where For the purpose of controlling the solenoids in t e broach handling; cylinder may be operated Y at valves 46 and 52, as well as a pair of solenoids through a sufficiently long stroke to completely, 66 and, which are connected to the operating clear a work piece having a deep recess with ut, lever 10 of the valve 22, an electrical control cirunnecessary increase in the time required for 01111; is Provided as follows! A-double thIOW P thus moving the broach idly. v button switch 12 normally establishes contact 5 .Further objects and advantages of the present from one side of a suitable D line Ll y 8011- invention will be apparent from the following deductors 14 and 16 to a single throw push button scription, reference being had to the accompanyswitch 18, which, in its normal position, connects ing drawing wherein a preferred form of the conductor" toa'conductor 80. The conductor present invention is clearly shown. 80 leads to both sides oi a double throw limit In the drawing: switch 86 adapted to beshifted by a cam 81 I The single figure represents a diagrammatic when the pistons 62 have moved up a predeterview of a power transmission system embodying mined distance. The limit switch 86 connects a preferred form of the present invention. by a conductor 88 with the right hand solenoid A tank l0 contains a supply of oil which may of the valve 52. All of the solenoids have their opposite sides connected to line L2. The limit switch 86, when shifted connects conductor 80 to a conductor 94 which extends through a safety switch 95 to the operating coil of a holding relay 96 and thence by a conductor 98 through a normally closed limit switch I to the line L2. Limit switch I00 is adapted to be opened by a cam IOI whenever piston 36 reaches the top of its stroke. The holding circuit for the relay 96 as well as the controlled circuits thereof connect with LI through switch I2, conductor I4 and a conductor I02. One controlled circuit extends from the relay 96 by a conductor I04 to the solenoid 66 of the valve 22. The other controlled circuit extends -by a conductor I to the right hand solenoid-of valve 46.

The normally open contacts of the switch I2 are adapted to establish a circuit from line LI by a conductor I06 to a conductor I08, leading to the operating coil of a holding relay H0. The

other side of the operating coil connects by a conductor I I2 with the contacts of a normally closed limit switch H4 and thence to line L2. The limit switch H4 is adapted to be shifted by a cam II5 whenever the pistons 62 start upwardly. The holding circuit for the relay IIO extends by a conductor H6 and conductor I06 switch I20 extend by conductors I24 and I26 to the left hand solenoids of the valves 52 and 46.

In operation with the pumps I-4 and 38 running, oil delivered by the pump I4 through con-.

duit I6 is by-passed to tank through the valve 22, which is normally spring centered, and through conduit'24.- With the valve 46 in its left hand position, as shown, the delivery of pump 38 is by-passed to tank through conduit 42, valve 46, conduit 50, valve 52 and conduit 54. Under these conditions the system remains at rest. circuit is established from the line LI through the switch I2, conductors I4 and I6, switch I8, conductor 80, limit switch 86 and conductor 88, to the right hand solenoid of the valve 52. Valve 52 shifts to the.right to connect the conduit 50 with the conduit 56 thus admitting pressure oil conduits 54 and 48 to the tank. 60"

from the pump 38 to the lower end of the cylinders 60. The pistons 62, accordingly, move upwardly discharging oil from the upper ends of cylinders 60 through conduit 58, valve 52 and Previous to depressing the. starting button I8 a work piece such as I32 may have been positioned beneath the work holding abutment I34 so that, as the pistons .62 move upwardly the broaching tool I 36, which is removably secured in a socket I38 carried by the pistons 62 is inserted' through the holes in the work piece I32 and abutment I34 and engaged in thetool clutch, carried by the slide 30. This movement is but a small part of the total stroke of the piston 62. As the tool I36 reaches a position in which it becomes locked in the tool clutch in the well known manner, cam 8I rides ofi limit switch 86. With the operator still holding the starting button depressed, a circuit is established from LI through switch I2, conductors I4, and I6, switch When starting button I8 is depressed a 'normal position, to line L2.

I8, conductor 80, limit switch 86, conductor 94, operating coil of relay 96, conductor 98, limit switch I 00 and line L2. Relay 96, accordingly,

closes, establishing its own holding circuit and Valve 22, accordingly, shifts to the right, connecting the pressure port to the left hand cylinder port and causing a flow of oil from pump I4 through conduit I6, valve 22 and conduit, 28 to the head end of cylinder 34. At the time that cam 81 rode off from limit switch 86, the latter also opened the circuitthrough conductor 88 to the right hand solenoid of valve 52. Valve 52 accordingly spring centers while valve 46 moves to its right hand position due to energization of the circuit I05. The delivery of pump 38 is thus joined to the delivery of pump I4 through conduit 42, valve 46, conduit 64 and valve 22. In its center position, valve 52 also-connects conduits 56 and 58 together, thus by-passing the two ends of the cylinders 60, permitting the pistons 62 to be pulled upwardly by the slide 30 acting through the tool I36. The tool I36 is thus pulled through the work piece until the pistons 62 reach the end of their upward stroke with the clutch I38 just below the work piece I32. Continued upward movement of the slide 30 pulls the tool I36 out of the clutch I38 and on through the work piece I32 untilthe lower end of the tool is above the bottom surface of the abutment I34. At this point the cam IOI contacts the limit switch I00, opening the holding circuit 98-I02 for relay 96, which accordingly, opens circuits I04 and I05 for the solenoid 66 and the right hand solenoid of valve 46. The valve 22 is accordingly permitted to spring center thus by-passing the delivery of pump I4 to the tank as before and by-pa'ssing pump 38'through conduit '42, valve 46 and conduit 64 to valve 22 and tank. The system thus comes to rest with both pistons 62 and cylinder 34 in their uppermost positions.

At this. time, the finished work piece may be retrieved or permitted to fall from its working position and the reverse button I2 may then be depressed. A circuit is thus established from line LI throughconductor I06, switch I2, conductor I08,-'operating coil of relay IIO, conductor II 2 and limit switch II4, which is now in its The relay IIO, accordingly, closes, establishing its own holding circuit and establishing a circuit from line LI by conductors I06 and H6, conductor II8,- limit switch I20, which is now in its normal position, and conductor I2 2 to solenoid 68. Valve 22 is accordingly moved to the left to connect the delivery of pumps I4 and 38 with conduit 26 thus admitting oil to the rod end of cylinder 34, causing the piston 36 to move downwardly. As soon as the tool I36 has been moved down sufliciently to engage the clutch I38, the pistons 62 are pushed downwardly for the rest of the stroke of the cylinder 34. Valve 52 remains spring centered, by-passing thecylinders 60 for this purpose. As the piston 36 reaches its lowermost position, cam I2I depresses limit switch I20, thus breaking the circuit to solenoid 68, permitting valve 22 to spring center and by-pass pump I4, and establishing two new circuits extending from LI by conductors I 06, H6, relay I I0, conductor I I8, switch I20, conductors I24, and I26 to the left hand solenoids of valves 52 and 46. These valves move to the left connecting the delivery conduits 50 and 58, thus admitting pressure oil to move the pistons 62 farther down. The tool clutch at slide 30 having been released by suit- 5 able mechanism at the bottom of the stroke of piston 36, the tool 36 is carried downwardly to the starting position shown. As the pistons 52 reach this position, cam I I5 contacts limit switch Ill thus opening the holding circuit ll2l it of relay H which opens to deenergize 'the left hand solenoids of valves 45 and 52. The latter spring centers, and since the former remains in its lefthand position, as shown, the pump 38 is by-passed, through valve 52. The system, accordingly, comes to rest and a new work piece may be placed in working position and the same cycles of operation repeated.

Fol-the purpose of controlling the rate of travel of piston 36 on its upward stroke, a suitable flow control valve, indicated at I42, may be connected by a conduit I to the conduit 28. Such a valve may serve in the manner well known in the art to by-pass the proper amount of oil required to maintain a constant rate of flow through the conduit 28 under all variations of resistance encountered in pulling the tool through the work. The safety switch 95 may be connected to be operated by the tool clutch on the slide 30 in a suitable manner so as to remain open if the tool should for any reason not properly engage in the clutch.

While the form of embodiment of the invention as herein disclosed, constitutes'a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What is claimed is as follows:

1. In a hydraulic power transmission system the combination of a main fluid motor and an auxiliary fluid motor, said motors being movable through forward and reverse strokes in the same directions, pump means'forming a source of fluid under pressure for operating said motors, means for controlling the supply of fluid to said motors, means forming a separable mechanical connection between said motors, and a control circuit for operating the control means to cause said motors to move through a cycle'of non-simultaneous but concurrent forward and reverse strokes, the main motor operating the auxiliary motor by said mechanical connection during the concurrent portion of said strokes.

2. In a hydraulic power transmission system the combination of a main fluid motor and an auxiliary fluid motor, said motors being movable through forward and reverse strokes in the same directions, pump means forming a source of fluid under pressure for operating said motors, means for controlling the supply of fluid to said motors, means forming a separable mechanicalconnection between said motors, and a control circuit for operating the control means to cause said motors to move through a cycle of non-simultaneous but concurrent forward and reverse strokes, the main motor operating the auxiliary motor by said mechanical connection during the 75 source of fluid under pressure for operating said motors, means for controlling the supply of fluid to saidmotors, means forming a separable mechanical connection between said motors, and a control circuit for. operating the control means to cause said motors to move through a cycle of non-simultaneous but concurrent forward and reverse'strokes, the main motor operating the auxiliary motor by said mechanical connection during the concurrent portion of said, strokes and means for by-passing the auxiliary motor during mechanical operation by the main motor, said'control means including a valve for connecting said pumps in parallel, and common means for by-passing the delivery of both pumps while connected in parallel.

4. In a hydraulic power transmission system the combination'of a main fluid motor and an auxiliaryfluid motor, said motors being movable through forward and-reverse strokes in the same directions, a pair of pump means forming a source of fluid under pressure for operating said motors, means for selectively connecting the main motor to one pump forforward or reverse operation or for by-passing the pump, means for selectively connecting the other pump either to the -flrst pump or to a separate delivery line, and means for selectively connecting the delivery line to the auxiliary motor for forward or reverse operation- 5. In a hydraulic power transmission system the combination of a main fluid motor and an auxiliary fluid motor, said motors being movable through forward and reverse strokes in the same directions, a pair of pump means forming a source of fluid under pressure for operating said motors, means for selectively connecting the main motor to one pump for forward or reverse operation or for by-passing the pump, means for selectively connecting the other pump either to the first pump or to a separate delivery line, and means for selectively connecting the delivery line to the auxiliary motor for forward orreverse operation, said last means being also operable to by-pass the auxiliary motor, and means forming a separable mechanical connection for at times driving the auxiliary motor from themain motor. f

-6. In a broaching machine having a main slide for pulling a broach tool through a work piece anda tool handling slide the combination of a main fluid motor for operating, the main slide, an auxiliary motor for operating the tool handling slide, pump means for supplying fluid to operate the motors, means for controlling the supply of fluid to the motors, a control circuit including means for operating the control means to cause the tool handling slide to move toward the main slide and means operable when the tool has engaged the main slide for causing the main slide to move through a broaching stroke and for by-passing the auxiliary motor to permit the tool handling slide, to follow the main slide.

1. In a broaching machine having a main slide for pulling a broach tool through a work piece and a tool handling slide the combination of a main fluid motor for operating the main slide, an, auxiliary motor for operating the tool handling slide, a main pump for supplying fluid to the main motor, an auxiliary pump for supplying fluid to the auxiliary motor, means for selectively connecting the main pum'p to either end for selectively connecting the two pumps in parallel. I

8. In a hydraulic power transmission system the combination of a main fluid motor and an auxiliary fluid motor, said motors being movable through forward and reverse strokes in the same directions, a main pump for supplying fluid to the main motor, an auxiliary pump for supplying fluid to the auxiliary motor, means for selectively connecting the main pump to either end of the main motor or to exhaust, means for selectively connecting the auxiliary motor to the allel.

HUGH C. NYE. 

